JP6282831B2 - User terminal, base station, and wireless communication method - Google Patents

Description

  The present invention relates to a user terminal, a base station, and a radio communication method applicable to a next generation communication system.

  In the UMTS (Universal Mobile Telecommunications System) network, Long Term Evolution (LTE) has been specified for the purpose of higher data rate and low delay (Non-patent Document 1). LTE uses a multi-access scheme based on OFDMA (Orthogonal Frequency Division Multiple Access) for the downlink (downlink) and SC-FDMA (single carrier frequency division multiple access) for the uplink (uplink). Is used. In addition, a successor system of LTE (for example, sometimes referred to as LTE Advanced or LTE enhancement (hereinafter referred to as “LTE-A”)) has been studied and specified for the purpose of further broadbandization and higher speed from LTE. (Rel. 10/11).

  Frequency division duplex (FDD) that divides uplink (UL) and downlink (DL) by frequency as duplex format (Duplex-mode) in radio communication of LTE and LTE-A systems, and uplink and downlink And time division duplex (TDD) that divides the time by time (see FIG. 1A). In the case of TDD, the same frequency region is applied to uplink and downlink communication, and uplink and downlink are divided by time from one transmission / reception point, and signals are transmitted and received.

  As another duplex format, there is a Half Duplex FDD (half duplex FDD) system. The Half Duplex FDD scheme is a communication scheme in which different frequency regions are allocated to the uplink and the downlink as in the FDD scheme, while uplink transmission and downlink transmission are not performed simultaneously for a certain user terminal. That is, for a certain user terminal, uplink transmission and downlink transmission are separated by time. The point that the uplink transmission and the downlink transmission are separated by time is the same as the operation of the TDD scheme.

  Further, the system band of the LTE-A system (Rel. 10/11) includes at least one component carrier (CC: Component Carrier) having the system band of the LTE system as a unit. Collecting a plurality of component carriers (cells) to increase the bandwidth is called carrier aggregation (CA).

3GPP TS 36.300 “Evolved UTRA and Evolved UTRAN Overall description”

  As described above, in FDD, transmission is performed using different frequency bands obtained by dividing UL and DL (Full-duplex). UL and DL are divided in the frequency direction. However, depending on the capability of the user terminal and the arrangement of the UL and DL frequencies, UL transmission can interfere with DL transmission, and DL reception and UL transmission can be performed simultaneously. There may not be. On the other hand, such a problem does not occur in TDD or Half Duplex FDD which performs communication by dividing UL and DL by time.

  For example, a user terminal to which FDD Full-duplex is applied implements a duplexer so that a UL signal transmitted from the user terminal does not interfere with a receiver for receiving a DL signal in the user terminal. Yes. However, simultaneous transmission / reception of the UL signal and the DL signal cannot be performed depending on a user terminal in which the duplexer is not mounted (or the performance of the duplexer is low), the arrangement of UL and DL frequencies, and the like. Therefore, conventionally, in order to solve such a problem, simultaneous transmission / reception is restricted by applying the Half Duplex FDD to user terminals that cannot perform simultaneous transmission / reception.

  By the way, Rel. In carrier aggregation (CA) introduced in 10/11, Duplex-mode applied between multiple CCs (also referred to as cells and transmission / reception points) is limited to the same Duplex-mode (see FIG. 1B). . On the other hand, in a future radio communication system (for example, Rel.

  In this case, the user terminal uses at least three different frequency bands of the FDD DL frequency band, the FDD UL frequency band, and the TDD DL / UL frequency band. For this reason, depending on the transmission / reception capability of the user terminal, the frequency band position where CA is performed (for example, the frequency band position of FDD and TDD), etc., the throughput due to the degradation of the reception quality of the user terminal due to simultaneous transmission / reception or the unreasonable limitation of simultaneous transmission / reception There is a risk that the transmission and reception of the user terminal cannot be performed properly.

  The present invention has been made in view of such a point, and even when performing CA by applying a Duplex-mode that is different among a plurality of cells, a user terminal and a base that can appropriately perform transmission and reception in the user terminal Another object is to provide a station and a wireless communication method.

The user terminal of the present invention is a user terminal that communicates with the FDD cell and the TDD cell using carrier aggregation, and transmits and receives a DL signal transmitted from each cell and a UL signal transmitted to each cell. has a signal section, and a notification control unit that controls the notification of the capability information relating to the simultaneous transmission and reception of the DL signal and the UL signal in the transceiver unit, the notification control unit is a frequency band and TDD cell to be used in FDD cell Control of notification of capability information regarding simultaneous transmission / reception of the transmission / reception unit for each combination of frequency bands to be used is controlled , and restrictions on simultaneous transmission / reception for each combination of frequency bands used in the FDD cell and frequency bands used in the TDD cell are defined in advance. DL signal received by the transceiver unit and / or transmitted by the transceiver unit UL signal is constrained and simultaneous transmission and reception predefined, with said capability information, characterized in that it is scheduled to constraints is greater condition.

  ADVANTAGE OF THE INVENTION According to this invention, transmission / reception in a user terminal can be appropriately performed even when performing CA by applying a duplex-mode that is different among a plurality of cells.

It is a figure for demonstrating the outline | summary of Duplex-mode in LTE and LTE-A, and CA (Intra-eNB CA) in base station. It is a figure for demonstrating CA (Inter-eNB CA) between base stations. It is a figure which shows an example in the case of applying different DL / UL structure between cells. It is a figure explaining the relationship of the example of arrangement | positioning of the frequency band of the FDD cell in TDD-FDD CA, and the frequency band of a TDD cell, and the simultaneous transmission / reception in a user terminal. It is a figure explaining the relationship of the example of arrangement | positioning of the frequency band of the FDD cell in TDD-FDD CA, and the frequency band of a TDD cell, and the simultaneous transmission / reception in a user terminal. It is a figure explaining the relationship of the example of arrangement | positioning of the frequency band of the FDD cell in TDD-FDD CA, and the frequency band of a TDD cell, and the simultaneous transmission / reception in a user terminal. It is a figure explaining the scheduling based on simultaneous transmission / reception of a user terminal in TDD-FDD CA. It is a figure which shows an example of the scheduling between the FDD cell and TDD cell in Inter-eNB CA. It is the schematic which shows an example of the radio | wireless communications system which concerns on this Embodiment. It is explanatory drawing of the whole structure of the wireless base station which concerns on this Embodiment. It is explanatory drawing of a function structure of the wireless base station which concerns on this Embodiment. It is explanatory drawing of the whole structure of the user terminal which concerns on this Embodiment. It is explanatory drawing of a function structure of the user terminal which concerns on this Embodiment.

  As described above, in LTE and LTE-A systems, FDD and TDD are defined as Duplex modes (see FIG. 1A above). Also, Rel. 10 supports an intra-base station CA (Intra-eNB CA). However, Rel. The CA in 10/11 was limited to the same Duplex-mode (FDD + FDD Intra-eNB CA or TDD + TDD Intra-eNB CA) (see FIG. 1B above).

  On the other hand, Rel. In the 12 and subsequent systems, intra-base station CA (Intra-eNB CA) to which different duplex modes (TDD + FDD) are applied among a plurality of CCs is assumed (see FIG. 1C above). Also, Rel. In the 12 and subsequent systems, application of inter-base station CA (Inter-eNB CA) is also assumed (see FIG. 2). The inter-base station CA is preferably supported without being limited to the duplex-mode, and an inter-base station CA including a different duplex-mode (TDD + FDD) may be introduced.

  Intra-base station CA (Intra-eNB CA) controls scheduling using a single scheduler among a plurality of cells. On the other hand, in inter-base station CA (Inter-eNB CA), a scheduler is provided independently for each of a plurality of cells, and scheduling is controlled in each cell. In the Inter-eNB CA, it is assumed that the connection between the base stations is a connection (Non-ideal backhaul connection) where the delay cannot be ignored.

  By the way, the user terminal may not be able to transmit and receive the UL signal and the DL signal at the same time (cannot be full-duplexed) due to the combination of frequency bands to which CA is applied or the implementation of the user terminal (duplexer performance). For example, when the frequency band used in the UL and the frequency band used in the DL are close to each other, there is a possibility that interference with the DL signal may occur due to unnecessary emission (Unwanted emissions) generated in the adjacent band when transmitting the UL signal. There is. In such a case, the user terminal cannot simultaneously transmit a UL signal and receive a DL signal.

  Also, when realizing the Full Duplex FDD scheme, it is necessary to mount a duplexer so that the UL signal does not interfere with the receiver that receives the DL signal in the user terminal. However, depending on the implementation status of the duplexer, it may be assumed that simultaneous transmission / reception of the UL signal and the DL signal cannot be performed.

  Therefore, in FDD, signaling (UE capability signaling) for a user terminal that cannot perform simultaneous transmission / reception to notify NW (for example, a base station) of capability information (Capability) regarding simultaneous transmission / reception is defined for each frequency band. For example, a user terminal that cannot simultaneously transmit a UL signal and receive a DL signal (cannot perform simultaneous transmission / reception) in an FDD cell notifies the base station to that effect.

  Specifically, a user terminal to which FDD is applied notifies whether a full-duplex or a half-duplex is used for each frequency band with one bit. In TDD, since UL and DL use the same frequency, the notification is not defined.

  On the other hand, Rel. 11 introduces that the transmission ratio of DL and UL is different between CCs (TDD inter-band CA with different UL-DL configuration) for each of a plurality of cells (base stations) to which TDD-TDD CA is applied. It was done. A case where a different DL / UL configuration is applied to each cell will be described below.

  Rel. For TDD in up to 10 systems, multiple patterns of UL and DL configuration ratios are defined (DL / UL Configuration0-6), and DL subframes assigned to each UL subframe are determined in each DL / UL configuration. ing. For example, FIG. 3A shows a case where each cell (Cell # 1, 2) applies DL / UL configuration 3 (DL / UL Config. 3). In FIG. 3B, one cell (Cell # 1) applies DL / UL configuration 3 (DL / UL Config. 3), and the other cell (Cell # 2) has DL / UL configuration 4 (DL / UL This shows a case where Config.4) is applied.

  As shown in FIG. 3A, when the same DL / UL configuration is applied between different cells, simultaneous transmission / reception of DL signals and UL signals does not occur at the user terminal. On the other hand, as shown in FIG. 3B, when different DL / UL configurations are applied to different cells, simultaneous transmission / reception of DL signals and UL signals may occur in the user terminal.

  As described above, when different DL / UL configurations are applied between different cells, the user terminal transmits a UL signal depending on a combination of frequency bands to which CA is applied or user terminal implementation (duplexer performance). And the DL signal cannot be transmitted and received at the same time.

  In order to solve such a problem, even in the TDD inter-band CA with different UL-DL configuration, a user terminal that cannot perform simultaneous transmission / reception notifies the NW (eg, base station) of information regarding the capability of simultaneous transmission / reception. Signaling (UE capability signaling) was introduced. For example, a user terminal that can perform simultaneous transmission and reception notifies the base station of that fact (for example, whether simultaneous transmission (simultaneous Rx-Tx) is possible). Specifically, when different DL / UL configurations are allowed between cells in TDD-TDD CA, the user terminal supports simultaneous transmission / reception (simultaneous Rx-Tx) for each frequency band combination to perform CA. Notify the base station.

  Therefore, even when CA is performed by applying different Duplex-modes among a plurality of CCs (cells) (TDD-FDD CA), it is conceivable to notify the above-described capability information regarding simultaneous transmission / reception from the user terminal.

  However, the present inventors have found that there are a plurality of cases where user terminals cannot simultaneously transmit / receive in TDD-FDD CA, and in existing signaling, the reception quality of user terminals decreases due to simultaneous transmission / reception, and throughput decreases due to unreasonable restrictions on simultaneous transmission / reception. Has been found to occur. The case where simultaneous transmission / reception is impossible in TDD-FDD CA will be described below. In addition, the arrangement configuration of the frequency bands of the FDD cell and the TDD cell shown in FIGS. 4 to 6 below is an example, and is not limited thereto.

  As shown in FIG. 4A, there may be a case where a full-duplex cannot be performed by FDD in TDD-FDD CA. In this case, since the user terminal cannot simultaneously transmit and receive the UL signal and the DL signal in the FDD cell, Half-duplex is applied.

  Alternatively, as shown in FIG. 4B, there may be a case where simultaneous transmission / reception is not possible using the FDD DL and the TDD UL in TDD-FDD CA. In this case, the user terminal can simultaneously receive the Full-duplex in the FDD cell, the UL frequency band of the FDD cell, and the DL frequency band of the TDD cell. In TDD, the frequency bands of UL and DL do not change, and UL and DL are switched and controlled in the time domain.

  Alternatively, as shown in FIG. 5A, there may be a case where simultaneous transmission / reception cannot be performed using the FDD UL and the TDD DL in TDD-FDD CA. In this case, the user terminal can simultaneously receive the Full-duplex in the FDD cell, the DL frequency band of the FDD cell, and the UL frequency band of the TDD cell.

  Alternatively, as shown in FIG. 5B, in TDD-FDD CA, there may be a case where simultaneous transmission / reception is not possible over the entire CA frequency. In this case, the user terminal cannot simultaneously transmit and receive the UL signal and the DL signal regardless of the FDD cell and the TDD cell.

  As described above, when TDD-FDD CA is applied, there are a plurality of cases in which simultaneous transmission / reception of the user terminal DL signal and the UL signal is disabled according to the combination of frequency bands. In this case, it is assumed that the user terminal applies the capability information signaling related to the simultaneous transmission and reception described above. In addition, in the signaling of capability information for simultaneous transmission / reception described above, (1) when full-duplex cannot be performed within the CC of FDD (controlled by half-duplex notification), and (2) when simultaneous transmission / reception cannot be performed over the entire frequency of CA ( (Controlled by Simultaneous Rx-Tx notification)).

  For example, it is assumed that the user terminal cannot perform simultaneous transmission / reception in the FDD DL frequency band and the TDD UL frequency band (see FIG. 4B). In this case, if the user terminal uses FDD Half-duplex notification, it is considered that FDD UL and FDD DL cannot be transmitted / received simultaneously, and simultaneous transmission / reception in FDD DL and TDD UL can be restricted. No (see FIG. 6A). In other words, an unreasonable assignment restriction occurs for the FDD cell, and assignment restriction cannot be performed between the FDD cell and the TDD cell.

  Further, if the user terminal uses a Simultaneous Rx-Tx notification that restricts simultaneous transmission and reception over the entire CA frequency, it is considered that simultaneous transmission and reception is not possible over the entire FDD and TDD frequencies (see FIG. 6B). As a result, the FDD UL and the FDD DL, which are originally capable of simultaneous transmission / reception, are also considered to be incapable of simultaneous transmission / reception, causing a problem of being unduly limited. Furthermore, simultaneous transmission and reception in the UL frequency band of FDD and the DL frequency band of TDD is also restricted.

  Therefore, the present inventors, when TDD-FDD CA is applied, the user terminal is related to simultaneous transmission / reception for each combination of the DL frequency band and UL frequency band in FDD and the DL / UL frequency band in TDD. Inspired to signal capability information. As a result, the NW correctly grasps the simultaneous transmission / reception capability of the user terminal in each frequency band of TDD and FDD and performs scheduling, thereby reducing the reception quality of the user terminal due to simultaneous transmission / reception and the throughput due to the unreasonable limitation of simultaneous transmission / reception. Can be suppressed. Hereinafter, the present embodiment will be described in detail.

(First aspect)
In the first aspect, for TDD-FDD CA, notification of capability information regarding simultaneous transmission / reception (Simultaneous Rx-Tx Capability Signaling) is introduced for each frequency band combination (CA Band combination) to which CA is applied. explain.

  Specifically, the information regarding applicability of simultaneous transmission / reception is defined as the frequency band combination parameter signaling for each individual frequency band combination (CA Band combination). The frequency band combination parameter (BandCombinationParameters) defines the CA bandwidth in DL or UL and the number of MIMO layers in DL or UL for each combination of frequency bands to be CA.

  In this case, capability information regarding simultaneous transmission / reception is defined as a band combination parameter (BandCombinationParameters) in an information element (UE-EUTRA-Capability information element) that defines the capability of the user terminal. The user terminal notifies the NW (for example, base station) of capability information regarding simultaneous transmission / reception defined in each band combination parameter as user terminal capability information (UE capability signaling). That is, each band combination parameter is defined in association with whether or not simultaneous transmission / reception is possible for the band combination.

  As capability information regarding simultaneous transmission / reception, applicability of simultaneous transmission / reception of the user terminal to the combination of the DL frequency band of the FDD cell and the UL frequency band of the TDD cell, the UL frequency band of the FDD cell, and the DL frequency band of the TDD cell It is possible to define information regarding applicability of simultaneous transmission / reception of user terminals with respect to the combination. Furthermore, information (Full-duplex) that does not require simultaneous transmission / reception restrictions for each frequency band and information that cannot be simultaneously transmitted / received over the entire CA frequency are defined. The user terminal determines its own simultaneous transmission / reception capability for each combination of frequency bands and notifies the base station.

  For example, as the capability information regarding simultaneous transmission / reception, the user terminal cannot perform simultaneous transmission / reception with (1) Full-duplex (no restriction on simultaneous transmission / reception), (2) FDD DL and TDD UL, and (3) FDD UL and TDD. It is possible to select and notify any of the stipulated that simultaneous transmission / reception is not possible using DL, or (4) simultaneous transmission / reception is not possible for the entire CA frequency. In this case, capability information regarding simultaneous transmission / reception can be defined by 2 bits.

  Here, it is assumed that the user terminal cannot perform simultaneous transmission / reception in the DL frequency band of FDD and the UL frequency band of TDD (see FIG. 4B). In this case, the user terminal notifies the NW that simultaneous transmission / reception is not possible using the FDD DL and the TDD UL as capability information regarding simultaneous transmission / reception. Thereby, each base station can correctly grasp the capability of the user terminal regarding simultaneous transmission and reception, and can appropriately schedule UL signals and DL signals in each frequency band (see FIG. 7).

  As described above, even in the TDD-FDD CA, a configuration is used to notify the applicability of simultaneous transmission / reception of the user terminal to the combination of the DL frequency of the FDD cell, the UL frequency band, and the DL / UL frequency band of the TDD cell. The NW can correctly grasp the capability regarding simultaneous transmission / reception of each user terminal. Then, each base station to which CA is applied performs scheduling control based on the capability of each user terminal regarding simultaneous transmission / reception, thereby reducing the reception quality of the user terminal due to simultaneous transmission / reception and throughput due to unreasonable limitation of simultaneous transmission / reception. The decrease can be suppressed.

(Second aspect)
A 2nd aspect demonstrates the case where the notification of the capability information regarding simultaneous transmission / reception is introduce | transduced for every user terminal for TDD-FDD CA. That is, in the second mode, capability information signaling is introduced for each individual user terminal.

  In this case, in the information element (UE-EUTRA-Capability information element) that defines the capability of the user terminal, capability information (for example, Simultaneous Rx-Tx) related to simultaneous transmission and reception is specified to control notification. Capability information regarding simultaneous transmission / reception includes (1) Full-duplex (no restrictions on simultaneous transmission / reception), (2) Simultaneous transmission / reception between FDD DL and TDD UL, (3) Simultaneous transmission / reception via FDD UL and TDD DL The information that (4) simultaneous transmission / reception is not possible over the entire frequency of CA can be defined by 2 bits. The user terminal selects either one according to the simultaneous transmission / reception capability of the user terminal and notifies the base station.

  Note that simultaneous transmission / reception restrictions for each frequency band combination (CA Band combination) can be defined in advance. As a restriction of simultaneous transmission / reception with respect to each combination of the UL frequency band of FDD, the DL frequency band, and the DL / UL frequency band of TDD, for example, the content of the simultaneous transmission / reception capability defined for each user terminal ((1) to (4)) It can be defined in the same way.

  In this case, the base station of each cell controls scheduling for each user terminal based on capability information regarding simultaneous transmission / reception notified from the user terminal and applicability of simultaneous transmission / reception for each predefined frequency band combination. In this case, if the capability information related to simultaneous transmission / reception notified from the user terminal and the simultaneous transmission / reception restriction condition for each frequency band combination specified in advance are different, the base station performs scheduling according to the condition with the larger restriction. Can be controlled.

  As described above, even in the TDD-FDD CA, a configuration is used to notify the applicability of simultaneous transmission / reception of the user terminal to the combination of the DL frequency of the FDD cell, the UL frequency band, and the DL / UL frequency band of the TDD cell. The NW can correctly grasp the capability regarding simultaneous transmission / reception of each user terminal. Then, each base station to which CA is applied performs scheduling control based on the capability of each user terminal regarding simultaneous transmission / reception, thereby reducing the reception quality of the user terminal due to simultaneous transmission / reception and throughput due to unreasonable limitation of simultaneous transmission / reception. The decrease can be suppressed. Further, in the second mode, it is not necessary to report simultaneously transmission / reception restrictions for each combination for each frequency band as capability information signaling, so that the overhead of capability information signaling (Capability signaling) can be reduced.

(Third aspect)
In the third mode, similar to the second mode, a notification of capability information regarding simultaneous transmission / reception is introduced for each user terminal for TDD-FDD CA. On the other hand, the base station controls the scheduler with no restriction on simultaneous transmission / reception for each frequency band combination (CA Band combination).

  As capability signaling (capability information related to simultaneous transmission / reception) transmitted for each user terminal, (1) Full-duplex (no restrictions on simultaneous transmission / reception), (2) DL of FDD and TDD, as in the second aspect. Information indicating that simultaneous transmission / reception cannot be performed by UL, (3) simultaneous transmission / reception by UL of FDD and DL of TDD, and (4) simultaneous transmission / reception cannot be performed by the entire CA frequency can be defined by two bits. In addition, the user terminal selects either one according to the simultaneous transmission / reception capability of the user terminal and notifies the base station.

  On the other hand, in the third mode, since the restriction condition of simultaneous transmission / reception for each CA frequency band combination (CA Band combination) is not notified to the user terminal, the base station performs scheduling when there is a restriction for each frequency band combination. Control when. At this time, if the capability information related to simultaneous transmission / reception notified from the user terminal and the simultaneous transmission / reception restriction conditions for each frequency band combination are different, the base station may control scheduling according to the condition with the larger restriction. it can.

(Modification)
In addition, this Embodiment (for example, the said 1st-3rd aspect) is not restricted to Intra-eNB CA, It is also possible to apply to Inter-eNB CA. In the case of Inter-eNB CA, dynamic cooperation is difficult between base stations that perform CA as described above. However, based on notification of capability information regarding simultaneous transmission / reception from user terminals, It can perform static (Semi-static) cooperation. This enables control to avoid simultaneous transmission / reception between different frequency bands.

  For example, it is assumed that simultaneous transmission / reception is not possible using the FDD DL and the TDD UL. In this case, at the timing when the DL of the FDD and the UL of the TDD occur at the same time, the allocation (scheduling) to only one of them is switched in time. For example, in a subframe in which an FDD DL and a TDD UL overlap, a subframe in which no TDD UL allocation is performed and a subframe in which no FDD DL allocation is performed are appropriately switched in time and controlled (see FIG. 8A). ).

  Further, for example, a case is assumed where simultaneous transmission / reception is not possible using UL of FDD and DL of TDD. In this case, at the timing when the UL of the FDD and the DL of the TDD occur at the same time, the allocation (scheduling) to only one of them is switched in time. For example, in the subframe in which the FDD UL and the TDD DL overlap, the subframe in which the TDD DL is not allocated and the subframe in which the FDD UL is not allocated are appropriately switched in time and controlled (see FIG. 8B). ).

(Configuration of wireless communication system)
Hereinafter, an example of the radio communication system according to the present embodiment will be described in detail.

  FIG. 9 is a schematic configuration diagram of the radio communication system according to the present embodiment. Note that the radio communication system illustrated in FIG. 9 is a system including, for example, an LTE system or SUPER 3G. In this wireless communication system, carrier aggregation (CA) in which a plurality of basic frequency blocks (component carriers) having the system bandwidth of the LTE system as one unit can be applied. Further, this radio communication system may be called IMT-Advanced, or may be called 4G, FRA (Future Radio Access).

  The radio communication system 1 shown in FIG. 9 includes a radio base station 11 that forms a macro cell C1, and radio base stations 12a and 12b that are arranged in the macro cell C1 and form a small cell C2 that is narrower than the macro cell C1. . Moreover, the user terminal 20 is arrange | positioned at the macrocell C1 and each small cell C2. The user terminal 20 can connect to both the radio base station 11 and the radio base station 12 (dual connectivity). Further, intra-base station CA (Intra-eNB CA) or inter-base station CA (Inter-eNB CA) is applied between the radio base station 11 and the radio base station 12. One of the radio base station 11 and the radio base station 12 can apply FDD, and the other can apply TDD.

  Communication between the user terminal 20 and the radio base station 11 is performed using a carrier having a relatively low frequency band (for example, 2 GHz) and a narrow bandwidth (referred to as an existing carrier or a legacy carrier). On the other hand, a carrier having a relatively high frequency band (for example, 3.5 GHz) and a wide bandwidth may be used between the user terminal 20 and the radio base station 12, or between the user base 20 and the radio base station 11. The same carrier may be used. A new carrier type (NCT) may be used as a carrier type between the user terminal 20 and the radio base station 12. The wireless base station 11 and the wireless base station 12 (or between the wireless base stations 12) are wired (Optical fiber, X2 interface, etc.) or wirelessly connected.

  The radio base station 11 and each radio base station 12 are connected to the upper station apparatus 30 and connected to the core network 40 via the upper station apparatus 30. The upper station device 30 includes, for example, an access gateway device, a radio network controller (RNC), a mobility management entity (MME), and the like, but is not limited thereto. Further, each radio base station 12 may be connected to a higher station apparatus via the radio base station 11.

  The radio base station 11 is a radio base station having a relatively wide coverage, and may be referred to as an eNodeB, a macro base station, a transmission / reception point, or the like. The radio base station 12 is a radio base station having local coverage, and may be called a small base station, a pico base station, a femto base station, a Home eNodeB, a micro base station, a transmission / reception point, or the like. Hereinafter, when the radio base stations 11 and 12 are not distinguished, they are collectively referred to as a radio base station 10. Each user terminal 20 is a terminal that supports various communication schemes such as LTE and LTE-A, and may include not only mobile communication terminals but also fixed communication terminals.

  In a radio communication system, OFDMA (Orthogonal Frequency Division Multiple Access) is applied to the downlink and SC-FDMA (Single Carrier Frequency Division Multiple Access) is applied to the uplink as radio access schemes. OFDMA is a multi-carrier transmission scheme that performs communication by dividing a frequency band into a plurality of narrow frequency bands (subcarriers) and mapping data to each subcarrier. SC-FDMA is a single-carrier transmission scheme that reduces interference between terminals by dividing the system bandwidth into bands composed of one or continuous resource blocks for each terminal, and a plurality of terminals using different bands. is there.

  Here, communication channels used in the wireless communication system shown in FIG. 9 will be described. The downlink communication channel includes a PDSCH (Physical Downlink Shared Channel) shared by each user terminal 20 and a downlink L1 / L2 control channel (PDCCH, PCFICH, PHICH, extended PDCCH). User data and higher control information are transmitted by the PDSCH. PDSCH and PUSCH scheduling information and the like are transmitted by PDCCH (Physical Downlink Control Channel). The number of OFDM symbols used for PDCCH is transmitted by PCFICH (Physical Control Format Indicator Channel). HARQ ACK / NACK for PUSCH is transmitted by PHICH (Physical Hybrid-ARQ Indicator Channel). Moreover, scheduling information of PDSCH and PUSCH may be transmitted by the extended PDCCH (EPDCCH). This EPDCCH is frequency division multiplexed with PDSCH (downlink shared data channel).

  The uplink communication channel includes a PUSCH (Physical Uplink Shared Channel) as an uplink data channel shared by each user terminal 20 and a PUCCH (Physical Uplink Control Channel) that is an uplink control channel. User data and higher control information are transmitted by this PUSCH. Also, downlink radio quality information (CQI: Channel Quality Indicator), ACK / NACK, and the like are transmitted by PUCCH.

  FIG. 10 is an overall configuration diagram of the radio base station 10 (including the radio base stations 11 and 12) according to the present embodiment. The radio base station 10 includes a plurality of transmission / reception antennas 101 for MIMO transmission, an amplifier unit 102, a transmission / reception unit 103, a baseband signal processing unit 104, a call processing unit 105, and a transmission path interface 106. Yes.

  User data transmitted from the radio base station 10 to the user terminal 20 via the downlink is input from the higher station apparatus 30 to the baseband signal processing unit 104 via the transmission path interface 106.

  The baseband signal processing unit 104 performs PDCP layer processing, user data division / combination, RLC layer transmission processing such as RLC (Radio Link Control) retransmission control transmission processing, MAC (Medium Access Control) retransmission control, for example, HARQ transmission processing, scheduling, transmission format selection, channel coding, inverse fast Fourier transform (IFFT) processing, and precoding processing are performed and transferred to each transceiver 103. The downlink control channel signal is also subjected to transmission processing such as channel coding and inverse fast Fourier transform, and is transferred to each transceiver 103.

  Moreover, the baseband signal processing part 104 notifies the control information for communication in the said cell with respect to the user terminal 20 by upper layer signaling (RRC signaling, an alerting signal, etc.). The information for communication in the cell includes, for example, system bandwidth in uplink or downlink, resource information for feedback, and the like. Each transmission / reception unit 103 converts the baseband signal output by precoding for each antenna from the baseband signal processing unit 104 to a radio frequency band. The amplifier unit 102 amplifies the frequency-converted radio frequency signal and transmits the amplified signal using the transmission / reception antenna 101.

  On the other hand, for data transmitted from the user terminal 20 to the radio base station 10 via the uplink, radio frequency signals received by the respective transmission / reception antennas 101 are amplified by the amplifier units 102 and frequency-converted by the respective transmission / reception units 103. It is converted into a baseband signal and input to the baseband signal processing unit 104.

  The baseband signal processing unit 104 performs FFT processing, IDFT processing, error correction decoding, MAC retransmission control reception processing, RLC layer, and PDCP layer reception processing on user data included in the input baseband signal. The data is transferred to the higher station apparatus 30 via the transmission path interface 106. The call processing unit 105 performs call processing such as communication channel setting and release, status management of the radio base station 10, and radio resource management.

  FIG. 11 is a main functional configuration diagram of baseband signal processing section 104 included in radio base station 10 according to the present embodiment. As illustrated in FIG. 11, the baseband signal processing unit 104 included in the radio base station 10 includes a control unit 301, a downlink control signal generation unit 302, a downlink data signal generation unit 303, a mapping unit 304, and a demapping unit. 305, a channel estimation unit 306, an uplink control signal decoding unit 307, an uplink data signal decoding unit 308, and a determination unit 309 are included.

  The control unit 301 controls scheduling of downlink user data transmitted on the PDSCH, downlink control information transmitted on the PDCCH and / or enhanced PDCCH (EPDCCH), downlink reference signals, and the like. The control unit 301 also performs control (allocation control) of uplink data transmitted on the PUSCH, uplink control information transmitted on the PUCCH or PUSCH, and uplink reference signal scheduling. Information related to allocation control of uplink signals (uplink control signals, uplink user data) is notified to user terminals using downlink control signals (DCI).

  Specifically, the control unit 301 controls allocation of radio resources for the downlink signal and the uplink signal based on the instruction information from the higher station apparatus 30 and the feedback information from each user terminal 20. That is, the control unit 301 has a function as a scheduler. Moreover, as shown in the said embodiment (1st-3rd aspect, modification), the control part 301 is based on the capability information regarding the simultaneous transmission / reception notified from a user terminal, DL signal of each frequency band, Controls UL signal allocation (scheduling).

  For example, when it is notified from the user terminal that simultaneous transmission / reception is not possible using the FDD DL and the TDD UL, the control unit 301 controls the scheduling of the UL signal and the DL signal of each frequency band, thereby controlling the DL of the FDD. And TDD UL are not assigned simultaneously (see FIG. 7). In the Inter-eNB CA, the control unit 301 is provided independently for each of the plurality of CCs. In the Intra-eNB CA, the control unit 301 can be provided in common for the plurality of CCs. Moreover, in Intra-eNB CA, the control part 301 is quasi-static (Semi-static) cooperation with another base station via the transmission-line interface 106 based on the capability information regarding the simultaneous transmission / reception notified from the user terminal. (See FIG. 8 above).

  The downlink control signal generation unit 302 generates a downlink control signal (PDCCH signal and / or EPDCCH signal) whose assignment has been determined by the control unit 301. Specifically, the downlink control signal generation unit 302, based on an instruction from the control unit 301, DL allocation (DL assignment) for notifying downlink signal allocation information and UL grant for notifying uplink signal allocation information (UL grant) is generated.

  The downlink data signal generation unit 303 generates a downlink data signal (PDSCH signal). The data signal generated by the downlink data signal generation unit 303 is subjected to an encoding process and a modulation process according to an encoding rate and a modulation scheme determined based on CSI from each user terminal 20 or the like.

  Based on the instruction from the control unit 301, the mapping unit 304 allocates the downlink control signal generated by the downlink control signal generation unit 302 and the downlink data signal generated by the downlink data signal generation unit 303 to radio resources. Control.

  The demapping unit 305 demaps the uplink signal transmitted from the user terminal and separates the uplink signal. Channel estimation section 306 estimates the channel state from the reference signal included in the received signal separated by demapping section 305, and outputs the estimated channel state to uplink control signal decoding section 307 and uplink data signal decoding section 308.

  The uplink control signal decoding unit 307 decodes a feedback signal (such as a delivery confirmation signal) transmitted from the user terminal using the uplink control channel (PUCCH) and outputs the decoded signal to the control unit 301. Uplink data signal decoding section 308 decodes the uplink data signal transmitted from the user terminal through the uplink shared channel (PUSCH), and outputs the decoded signal to determination section 309. Based on the decoding result of uplink data signal decoding section 308, determination section 309 performs retransmission control determination (ACK / NACK) and outputs the result to control section 301.

  FIG. 12 is an overall configuration diagram of the user terminal 20 according to the present embodiment. The user terminal 20 includes a plurality of transmission / reception antennas 201 for MIMO transmission, an amplifier unit 202, a transmission / reception unit (reception unit) 203, a baseband signal processing unit 204, and an application unit 205.

  For downlink data, radio frequency signals received by a plurality of transmission / reception antennas 201 are respectively amplified by an amplifier unit 202, frequency-converted by a transmission / reception unit 203, and converted into a baseband signal. The baseband signal is subjected to FFT processing, error correction decoding, retransmission control reception processing, and the like by the baseband signal processing unit 204. Among the downlink data, downlink user data is transferred to the application unit 205. The application unit 205 performs processing related to layers higher than the physical layer and the MAC layer. Also, broadcast information in the downlink data is also transferred to the application unit 205.

  On the other hand, uplink user data is input from the application unit 205 to the baseband signal processing unit 204. The baseband signal processing unit 204 performs retransmission control (H-ARQ (Hybrid ARQ)) transmission processing, channel coding, precoding, DFT processing, IFFT processing, and the like, and forwards them to each transmission / reception unit 203. The transmission / reception unit 203 converts the baseband signal output from the baseband signal processing unit 204 into a radio frequency band. Thereafter, the amplifier unit 202 amplifies the frequency-converted radio frequency signal and transmits the amplified signal using the transmission / reception antenna 201.

  FIG. 13 is a main functional configuration diagram of the baseband signal processing unit 204 and the like that the user terminal 20 has. As illustrated in FIG. 13, the baseband signal processing unit 204 included in the user terminal 20 includes a control unit 401 (notification control unit), an uplink control signal generation unit 402, an uplink data signal generation unit 403, a mapping unit 404, The demapping unit 405, the channel estimation unit 406, the downlink control signal decoding unit 407, the downlink data signal decoding unit 408, and the determination unit 409 are included at least.

  The control unit 401 controls generation of an uplink control signal and an uplink data signal. The control unit 401 controls generation / notification of information (UE Capability) and the like related to the capability of the user terminal. That is, the control unit 401 also functions as a notification control unit for higher layer signals and the like.

  For example, as shown in the above embodiment (first to third aspects), the control unit 401 controls to notify the NW including the capability information related to simultaneous transmission / reception in the transmission / reception unit 203. Specifically, the control unit 401 performs control so that the capability information (UE Capability signaling) of the user terminal is included in the capability information (UE Capability signaling) of the user terminal and is notified to the NW. Capability information regarding simultaneous transmission / reception includes (1) Full-duplex (no restrictions on simultaneous transmission / reception), (2) Simultaneous transmission / reception between FDD DL and TDD UL, (3) Simultaneous transmission / reception via FDD UL and TDD DL The information that (4) simultaneous transmission / reception is not possible over the entire frequency of CA can be defined by 2 bits.

  The uplink control signal generation unit 402 generates an uplink control signal based on an instruction from the control unit 401. Further, the uplink data signal generation unit 403 generates an uplink data signal based on an instruction from the control unit 401. Note that the control unit 401 instructs the uplink data signal generation unit 403 to generate an uplink data signal when the UL grant is included in the downlink control signal notified from the radio base station.

  The mapping unit 404 (allocation unit) controls allocation of uplink control signals (such as delivery confirmation signals) and uplink data signals to radio resources (PUCCH, PUSCH) based on an instruction from the control unit 401. For example, the mapping unit 404 allocates a delivery confirmation signal to the PUCCH of the CC according to the CC (cell) that performs feedback (PUCCH transmission).

  The demapping unit 405 demaps the downlink signal transmitted from the radio base station 10 and separates the downlink signal. Channel estimation section 406 estimates the channel state from the reference signal included in the received signal separated by demapping section 405, and outputs the estimated channel state to downlink control signal decoding section 407 and downlink data signal decoding section 408.

  Downlink control signal decoding section 407 decodes the downlink control signal (PDCCH signal) transmitted on the downlink control channel (PDCCH), and outputs scheduling information (allocation information for uplink resources) to control section 401.

  Downlink data signal decoding section 408 decodes the downlink data signal transmitted on the downlink shared channel (PDSCH), and outputs the decoded signal to determination section 409. The determination unit 409 performs retransmission control determination (ACK / NACK) based on the decoding result of the downlink data signal decoding unit 408 and outputs the result to the control unit 401.

  Although the present invention has been described in detail using the above-described embodiments, it is obvious to those skilled in the art that the present invention is not limited to the embodiments described in this specification. The present invention can be implemented as modified and changed modes without departing from the spirit and scope of the present invention defined by the description of the scope of claims. For example, the above-described plurality of aspects can be applied in appropriate combination. Therefore, the description of the present specification is for illustrative purposes and does not have any limiting meaning to the present invention.

DESCRIPTION OF SYMBOLS 1 ... Wireless communication system 10 ... Wireless base station 11 ... Wireless base station (macro base station)
12, 12a, 12b ... wireless base station (small base station)
DESCRIPTION OF SYMBOLS 20 ... User terminal 30 ... Host station apparatus 40 ... Core network 101 ... Transmission / reception antenna 102 ... Amplifier unit 103 ... Transmission / reception unit 104 ... Baseband signal processing unit 105 ... Call processing unit 106 ... Transmission path interface 201 ... Transmission / reception antenna 202 ... Amplifier unit 203 ... Transmission / reception unit 204 ... Baseband signal processing unit 205 ... Application unit 301 ... Control unit (scheduler)
302 ... Downlink control signal generation unit 303 ... Downlink data signal generation unit 304 ... Mapping unit 305 ... Demapping unit 306 ... Channel estimation unit 307 ... Uplink control signal decoding unit 308 ... Uplink data signal decoding unit 309 ... Determination unit 401 ... Control unit (Notification control unit)
402 ... Uplink control signal generation unit 403 ... Uplink data signal generation unit 404 ... Mapping unit 405 ... Demapping unit 406 ... Channel estimation unit 407 ... Downlink control signal decoding unit 408 ... Downlink data signal decoding unit 409 ... Determination unit

Claims (9)

A user terminal that communicates with a FDD cell and a TDD cell using carrier aggregation,
The reception of the DL signal transmitted from each cell, and the transmission and reception unit for transmitting a UL signal for each cell,
A notification control unit that controls notification of capability information regarding simultaneous transmission and reception of DL signals and UL signals in the transmission and reception unit,
The notification control unit controls notification of capability information regarding simultaneous transmission / reception of the transmission / reception unit for each combination of a frequency band used in an FDD cell and a frequency band used in a TDD cell ,
Restrictions on simultaneous transmission and reception for each combination of a frequency band used in an FDD cell and a frequency band used in a TDD cell are defined in advance, and a DL signal received by the transmission / reception unit and / or a UL transmitted by the transmission / reception unit The user terminal is characterized in that the signal is scheduled according to a condition having a large restriction by using a restriction on simultaneous transmission / reception defined in advance and the capability information .   The capability information regarding the simultaneous transmission / reception includes the applicability of simultaneous transmission / reception of the transmission / reception unit to the combination of the DL frequency band of the FDD cell and the UL frequency band of the TDD cell, and the combination of the UL frequency band of the FDD cell and the DL frequency band of the TDD cell. The user terminal according to claim 1, further comprising: information regarding applicability of simultaneous transmission / reception of the transmission / reception unit for   The capability information on the simultaneous transmission / reception includes information on whether or not a full-duplex of the transmission / reception unit in the FDD cell is applicable and information on whether or not the simultaneous transmission / reception of the transmission / reception unit with respect to an entire frequency for carrier aggregation is applicable. The user terminal according to 2.   The said notification control part notifies the capability information regarding the said simultaneous transmission / reception as user terminal capability information, The user terminal in any one of Claims 1-3 characterized by the above-mentioned.   4. The user terminal according to claim 1, wherein the capability information related to simultaneous transmission / reception is defined as a parameter of the frequency band combination for each frequency band combination to which carrier aggregation is applied. . A base station that communicates with a user terminal by applying carrier aggregation to another base station that uses a different duplex format,
A receiving unit that receives capability information related to simultaneous transmission and reception of a DL signal and a UL signal in a user terminal;
A control unit that controls scheduling of the DL signal and the UL signal for the user terminal based on the simultaneous transmission and reception capability of the user terminal ;
The reception unit receives capability information regarding simultaneous transmission / reception of the user terminal for each combination of a frequency band used in the FDD cell and a frequency band used in the TDD cell as capability information of simultaneous transmission / reception of the user terminal ,
Restrictions on simultaneous transmission / reception for each combination of frequency bands used in the FDD cell and frequency bands used in the TDD cell are defined in advance, and the control unit determines the restrictions on simultaneous transmission / reception defined in advance and the capability information. A base station that uses and controls scheduling according to a condition with large constraints .   The base station according to claim 6, wherein the receiving unit receives the capability information of simultaneous transmission / reception of the user terminal as 2-bit user capability information.   When the inter-base station carrier aggregation is applied, the control unit does not collide the DL signal and / or UL signal allocation with the allocation of the other base station based on the capability information regarding the simultaneous transmission and reception of the user terminal. The base station according to claim 6, wherein the base station is controlled as follows. A wireless communication method of a user terminal that performs communication with an FDD cell and a TDD cell to which carrier aggregation is applied,
Receiving DL signals transmitted from each cell, and transmitting UL signals to each cell;
And notifying capability information regarding simultaneous transmission and reception of DL signals and UL signals in the user terminal,
The capability information related to simultaneous transmission / reception includes capability information related to simultaneous transmission / reception of the user terminal for each combination of a frequency band used in the FDD cell and a frequency band used in the TDD cell ,
Restrictions on simultaneous transmission and reception for each combination of a frequency band used in the FDD cell and a frequency band used in the TDD cell are defined in advance, and a DL signal received by the user terminal and / or a UL transmitted by the user terminal The wireless communication method according to claim 1, wherein the signal is scheduled according to a condition with a large restriction using a restriction on simultaneous transmission / reception defined in advance and the capability information .

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